Flavoring compositions produced by reacting hydrogen sulfide with a pentose

ABSTRACT

The flavoring compositions produced by the reaction of a pentose with hydrogen sulfide possess potent flavoring characteristics even though the reactants from which they are produced are markedly different from such compositions. For example, certain such compositions possess a characteristic meat flavor in a concentration as low as one part in 10,000 notwithstanding that one of the components for producing such compositions has an obnoxious odor. Such meat flavoring compositions significantly increase the degree of palatability of nonmeat protein.

United States Patent Gunther [54] FLAVORING COMPOSITIONS PRODUCED BYREACTING HYDROGEN [63] Continuation-in-part of Ser. No. 730,665, May 20,I968, abandoned, Continuation-impart of Ser. No. 746,240, July 22, 1968,abandoned.

[52] US. Cl ..99/140 R, 260/209 R, 260/126 R [51] Int. Cl. ..A23l1/26[58] Field of Search ..99/140; 260/209, 126

[56] References Cited UNITED STATES PATENTS 2,934,437 4/1960 Morton etal. ..99/140 3,394,015 7/1968 Giacino ..99/ I40 [4 1 Feb. 15,1972

FOREIGN PATENTS OR APPLICATIONS 276,602 l()/ 1951 Switzerland OTHERPUBLICATIONS Mecchi et al, Origin of Hydrogen Sulfide in Heated ChickenMuscle," Journal of Food Science, Vol. 29, I964 pp. 393- PrimaryExaminerMorris 0. Walk Assistant ExaminerWarren Bovee Att0rney-F rank M.Nolan 57] ABSTRACT The flavoring compositions produced by the reactionof a pentose with hydrogen sulfide possess potent flavoringcharacteristics even though the reactants from which they are producedare markedly different from such compositions. For example, certain suchcompositions possess a characteristic meat flavor in a concentration aslow as one part in 10,000 notwithstanding that one of the components forproducing such compositions has an obnoxious odor. Such meat flavoringcompositions significantly increase the degree of palatability ofnonmeat protein.

36 Claims, No Drawings FLAVORING COMPOSITIONS PRODUCED BY REACTINGHYDROGEN SULFIDE WITH A PENTOSE This application is acontinuation-in-part of the pending applications Ser. No. 730,665, filedMay 20, 1968, now abandoned, and Ser. No. 746,240, filed July 22, 1968,now abandoned.

This invention relates to flavoring compositions and more particularlyto flavoring compositions for foods and the processes for producingthem.

The increasing need to supply a growing world population withproteinaceous foods has led nutritionists to advocate nonmeat sourcesbecause their per acre yield of usable protein is so much higher thanthat of meat. However, tradition and taste preferences presentformidable opposition to the acceptance of plant proteins as majorcomponents of such food stuffs.

In accordance with this invention, flavoring compositions are providedwhich significantly increase the degree of palatability of nonmeatprotein. This addition renders such nonmeat proteinswhich arenutritionally equivalent to proteins in meatparticularly acceptable asfood.

The flavoring compositions of this invention are prepared by reacting apentose such as ribose, xylose, arabinose and lyxose with hydrogensulfide. Instead of a single pentose a plurality of pentoses may bereacted with the hydrogen sulfide. The reactants are desirably heated toa temperature between 90 C. and that at which the pentose decomposes.Preferably, the temperature is maintained between 100 and 120 C.Desirably, a pressure above atmospheric is employed, such as a pressureof to 40 pounds per square inch. This pressure may be obtained in aclosed Parr pressure reactor or other similar container. The reactionmay be conducted in the presence of a solvent for the pentose such aswater.

While satisfactory flavor reaction products are obtained with a widerange of proportions of reactants, preferred reaction products areproduced with a ratio of 1 mole of hydrogen sulfide to about 2 moles ofpentose.

Alternatively, the flavoring compositions of this invention may beprepared by producing the hydrogen sulfide in situ with a solidinorganic sulfide in the present of an acid. More particularly, in thisalternative procedure, the pentose is reacted with a solid inorganicsulfide. Desirably, the solid inorganic sulfide is nontoxic. Inaddition, it is desirable that the anion of the acid and the cation ofthe sulfide combine to produce a nontoxic compound. Preferably, thereactants employed to produce the flavoring composition and anyadditional reaction compound produced comply with all governmentregulations relating to food such as thosecompiled by the United StatesFood andDrug Administration for foodstuffs. Conveniently, the inorganicsulfide, pentose and acid are heated together in a sealed container suchas a sealed Parr Reactor at a temperature above 100 C. and less thanthat at which any decomposition occurred, such as 120 C. The heating ismaintained until the flavoring composition is produced which ismanifested by a pleasant odor such as a meaty odor. Usually a period ofabout I to minutes is sufficient for this purpose.

Examples of pentoses are ribose, xylose, arabinose and lyxose. Insteadof a single pentose a plurality of pentoses may be employed.

Examples of inorganic sulfides are ammonium sulfide, sodium sulfide,potassium sulfide and calcium sulfide. One or a plurality ofinorganicsulfides may be employed.

Examples of the acid are carboxylic acids such acetic acid, propionicacid, palmitic acid, succinic acid, fumaric acid, adipic acid and oleicacid; hydroxy carboxylic acids such as lactic acid, malic acid, citricacid and tartaric acid; dicarboxylicamino acids such as glutamic acid;and mineral acids such as hydrochloric acid, sulfuric acid andphosphoric acid.

The reactants are desirably heated to a temperature between 90 C. andthat at which the pentose decomposes. Preferably the temperature ismaintained between 100 C. and

I20 C. Desirably, a pressure above atmospheric is employed such as apressure of 20 to pounds per square inch. This pressure may be obtainedin a closed Parr Pressure Reactor or other similar container. Thereaction may be conducted in the presence of a solvent for the pentosesuch as water.

While satisfactory flavoring compositions are obtained with a wide rangeproportion of reactants, preferred flavoring compositions are producedwith the ratio of l mole of inorganic sulfide to about 2 moles ofpentose.

It is desirable not to use reactants for production of flavoringcompositions which contain undesired substances or which would beretained after a reaction has been completed. Desirably reactants shouldbe avoided which produce compositions in addition to the desiredflavoring compositions. and which might mask or otherwise interfere withthe desired flavor which stems from the flavoring compositions.

The flavor reaction products may be incorporated in any comestible. Forexample, such reactant products may be uniformly distributed invegetable proteins such as those described in Food Technology, Vol. 21,pp. 168471, Feb. 1967, in fish protein concentrate such as thatdescribed in Food Technology, Vol. 21, pp. 1604-4610, Dec., 1967, or infoods for domesticated animals. Such reaction products are particularlyuseful in meat substitute foods. While the quantity of such reactionproducts employed may vary over wide limits, a proportion by weight ofone part of reaction product to 500 to 100,000 parts of comestible andpreferably one part of reaction product to 2000 to 4000 parts ofcomestible may be used.

A more comprehensive understanding of this invention is obtained byreference to the following examples:

EXAMPLE I 303 grams of xylose (99 percent) (2 moles) are dissolved in250 ml. of water by heating in an open Parr pressure reactor. Thereactor is closed, the stirrer turned on and the temperature brought toC. 34 Grams (1 mole) of hydrogen sulfide are introduced with constantstirring over a period of 3 hours.

The reactor is vented and the contents cooled. The product has apronounced meat aroma and flavor when diluted in a ratio of l:l0,000with water.

EXAMPLE ll 3 Grams of pure ribose (0.02 mole) is dissolved in 2.5 ml. ofwater by heating in an open Parr pressure reactor. The reactor isclosed, the stirrer turned on and the temperature brought to 120 C. 0.34gram (0.0l mole) of hydrogen sulfide is introduced with constantstirring over a period of onehalf hour.

The reactor is vented and the contents cooled. The product has apronounced meat aroma and'flavor when diluted in a ratio of l 10,000with water.

EXAMPLE III Example [I is repeated except that 3 grams (0.02 mole) ofarabinose are employed instead of the 3 grams of ribose.

EXAMPLE IV Example II is repeated except that 3 grams (0.02 mole) oflyxose are employed instead of the 3 grams of ribose.

EXAMPLE V One gram of the reaction product of Example I is thoroughlymixed with 3 kilograms of the fish protein concentrate described in FoodTechnology, Vol. 21, pp. 1604-1610, Dec., 1967. The mixing is performedin a food blender. The incorporated reaction product imparts a pleasingmeatlike taste to the resulting mixture.

EXAMPLE VI 4.9 grams of glutamic acid, 5 g. of 22 percent ammoniumsulfide solution and 5 g. of xylose are placed in a Parr reactor. TheParr reactor is sealed and heated at 120 C. for 10 minutes. A flavoringcomposition is produced which gives a pleasant roasted meat flavor.

Alternatively 4.7 g. of glutamic acid, 4.0 g. of sodium sulfideenneahydrate, g. of xylose and 5 ml. of water are heated in a sealedParr reactor at 120 C. for minutes. A similar flavoring composition isproduced by this reaction.

EXAMPLE V1] 4.7 grams of glutamic acid, 3.3 g. of potassium sulfidepentahydrate, 5 g. of xylose and 5 ml. of water are heated in a sealedvessel at l20 C. for 10 minutes. The flavoring composition produced hasa pleasant flavor.

EXAMPLE VIII 4 grams of lactic acid in a 75 percent aqueous solution, 5g. of ammonium sulfide in a 22 percent solution and 5 g. of xylose areheated together in a Parr reactor to l20 C. for l0 minutes. Theflavoring composition produced has a pleasant meat flavor.

ln some cases an insoluble composition is produced. This is illustratedwith a pentose such as xylose, calcium sulfide and either sulfuric acidor phosphoric acid. Both leave an insoluble salt which can easily beseparated to leave essentially a pure flavoring composition having adefinite meat flavor. When sodium sulfide is reacted with xylose andhydrochloric acid, a flavoring composition and sodium chloride areproduced. The flavoring composition has a definite meat flavor. Thereaction of sodium chloride, glutamic acid and a pentose such as xyloseresults in a flavoring composition containing monosodium glutamate. Boththe composition and the monosodium glutamate individually contribute tothe flavor. When xylose and ammonium sulfide are reacted in the presenceof an eight fold excess of palmitic acid, a flavoring composition isproduced which has a definite meaty flavor.

What is claimed is:

1. The reaction product of a pentose and hydrogen sulfide produced byreacting said pentose and hydrogen sulfide in the presence of a neutralor acidic medium at a temperature below the decomposition temperatureofsaid pentose.

2. The reaction product of claim 1, in which the pentose is ribose.

3. The reaction product of claim 1 in which the pentose is xylose.

4. The reaction product of claim 1 in which the pentose is arabinose.

5. The reaction product of claim 1 in which the pentose is lyxose.

6. The process of producing the reaction product of claim 1 whichconsists essentially of reacting hydrogen sulfide with a pentose in thepresence of a neutral or acidic medium at a temperature below thedecomposition temperature of said pentose.

7. The process of claim 6 in which the neutral or acidic medium iswater.

8. The process of claim 6 in which the reaction is conducted at atemperature between C. and the decomposition temperature of the pentose.

9. The process of claim 6 in which the reaction is conducted at apressure above atmospheric.

10. The process ofclaim 6 in which the pentose is ribose.

11. The process ofclaim 6 in which the pentose is xylose.

12. The process of claim 6 in which the pentose is arabinose.

13. The process of claim 6 in which the pentose is lyxose.

14. A comestible having incorporated therein a reaction product of claim1.

15. A comestible of claim 14 in which the comestible is vegetableprotein.

16. A comestible of claim 14 in which the comestible is fish protein.

17. The process of claim 6 in which the reaction is conducted at atemperature below l20 C.

18. The process of claim 6 in which the reaction is conducted at atemperature between 90 C. and C.

19. The process of claim 6 in which the hydrogen sulfide is produced insitu by a solid inorganic sulfide in the presence of an acid.

20. The process of claim 19 in which the anion of the acid and thecation of the sulfide combine to produce a nontoxic compound.

21. The process of claim 19 in which the inorganic sulfide is nontoxic.

22. The process of claim 19 in which the acid is a carboxylic acid.

23. The process of claim 19 in which the acid is an hydroxy carboxylicacid.

24. The process of claim 19 in which the acid is a dicarboxylic aminoacid.

25. The process of claim 19 in which the acid is glutamic acid.

26. The process ofclaim 19in which the acid is acetic acid.

27. The process of claim 19 in which the acid is lactic acid.

28. The process of claim 19 in which the acid is malic acid.

29. The process of claim 19 in which the inorganic sulfide is ammoniumsulfide.

30. The process of claim 19 in which the inorganic sulfide is sodiumsulfide.

31. The process of claim 19 in which the inorganic sulfide is potassiumsulfide.

32. The process of claim 19 in which the inorganic sulfide is calciumsulfide.

33. The process of claim 19 in which the pentose is xylose.

34. The process of claim 19 in which the pentose is xylose and theinorganic sulfide is ammonium sulfide.

35. The process of claim 19 in which the pentose is xylose. theinorganic sulfide is ammonium sulfide and the acid is glutamic acid.

36. The process of claim 19 in which the pressure at which the reactionis conducted is 20 to 40 pounds per square inch.

2. The reaction product of claim 1, in which the pentose is ribose. 3.The reaction product of claim 1 in which the pentose is xylose.
 4. Thereaction product of claim 1 in which the pentose is arabinose.
 5. Thereaction product of claim 1 in which the pentose is lyxose.
 6. Theprocess of producing the reaction product of claim 1 which consistsessentially of reacting hydrogen sulfide with a pentose in the presenceof a neutral or acidic medium at a temperature below the decompositiontemperature of said pentose.
 7. The process of claim 6 iN which theneutral or acidic medium is water.
 8. The process of claim 6 in whichthe reaction is conducted at a temperature between 90* C. and thedecomposition temperature of the pentose.
 9. The process of claim 6 inwhich the reaction is conducted at a pressure above atmospheric.
 10. Theprocess of claim 6 in which the pentose is ribose.
 11. The process ofclaim 6 in which the pentose is xylose.
 12. The process of claim 6 inwhich the pentose is arabinose.
 13. The process of claim 6 in which thepentose is lyxose.
 14. A comestible having incorporated therein areaction product of claim
 1. 15. A comestible of claim 14 in which thecomestible is vegetable protein.
 16. A comestible of claim 14 in whichthe comestible is fish protein.
 17. The process of claim 6 in which thereaction is conducted at a temperature below 120* C.
 18. The process ofclaim 6 in which the reaction is conducted at a temperature between 90*C. and 120* C.
 19. The process of claim 6 in which the hydrogen sulfideis produced in situ by a solid inorganic sulfide in the presence of anacid.
 20. The process of claim 19 in which the anion of the acid and thecation of the sulfide combine to produce a nontoxic compound.
 21. Theprocess of claim 19 in which the inorganic sulfide is nontoxic.
 22. Theprocess of claim 19 in which the acid is a carboxylic acid.
 23. Theprocess of claim 19 in which the acid is an hydroxy carboxylic acid. 24.The process of claim 19 in which the acid is a dicarboxylic amino acid.25. The process of claim 19 in which the acid is glutamic acid.
 26. Theprocess of claim 19 in which the acid is acetic acid.
 27. The process ofclaim 19 in which the acid is lactic acid.
 28. The process of claim 19in which the acid is malic acid.
 29. The process of claim 19 in whichthe inorganic sulfide is ammonium sulfide.
 30. The process of claim 19in which the inorganic sulfide is sodium sulfide.
 31. The process ofclaim 19 in which the inorganic sulfide is potassium sulfide.
 32. Theprocess of claim 19 in which the inorganic sulfide is calcium sulfide.33. The process of claim 19 in which the pentose is xylose.
 34. Theprocess of claim 19 in which the pentose is xylose and the inorganicsulfide is ammonium sulfide.
 35. The process of claim 19 in which thepentose is xylose, the inorganic sulfide is ammonium sulfide and theacid is glutamic acid.
 36. The process of claim 19 in which the pressureat which the reaction is conducted is 20 to 40 pounds per square inch.